launcher: tell user when loader is missing

At the moment it will just do nothing and go back to menu; instead
print a hopefully helpful text that the file is missing.

arm9/source/launcher/AcekardLauncher.cpp

@@ -46,6 +46,11 @@ bool AcekardLauncher::launchRom(std::string romPath, std::string savePath, u32 f
 
     dbg_printf("load %s\n", romPath.c_str());
 
+    if (access("fat:/__rpg/akloader.nds", F_OK) != 0) {
+        printLoaderNotFound("fat:/__rpg/akloader.nds");
+        return false;
+    }
+
     // akloaders are very old and expect the old-style libfat mount points
     romPath.replace(0, 3, "fat0");
     savePath.replace(0, 3, "fat0");

arm9/source/launcher/ILauncher.h

@@ -7,6 +7,12 @@
 #pragma once
 
 #include <nds/ndstypes.h>
+#include "../language.h"
+#include "../ui/msgbox.h"
+
+static inline void printLoaderNotFound(std::string loaderPath) {
+    akui::messageBox(NULL, LANG("loader", "not found"), loaderPath, MB_OK);
+}
 
 class ILauncher {
   public:

arm9/source/launcher/NdsBootstrapLauncher.cpp

@@ -73,6 +73,12 @@ bool NdsBootstrapLauncher::prepareIni() {
 bool NdsBootstrapLauncher::launchRom(std::string romPath, std::string savePath, u32 flags,
                                      u32 cheatOffset, u32 cheatSize) {
     const char ndsBootstrapPath[] = SD_ROOT_0 "/_nds/nds-bootstrap-release.nds";
+
+    if (access(ndsBootstrapPath, F_OK) != 0) {
+        printLoaderNotFound(ndsBootstrapPath);
+        return false;
+    }
+
     std::vector<const char*> argv;
 
     mRomPath = romPath;

arm9/source/launcher/PassMeLauncher.cpp

@@ -16,6 +16,11 @@ bool PassMeLauncher::launchRom(std::string romPath, std::string savePath, u32 fl
                                u32 cheatOffset, u32 cheatSize) {
     const char passMeLoaderPath[] = "fat:/__rpg/PassMeLoader.nds";
 
+    if (access(passMeLoaderPath, F_OK) != 0) {
+        printLoaderNotFound(passMeLoaderPath);
+        return false;
+    }
+
     std::vector<const char*> argv;
     argv.push_back(passMeLoaderPath);
     eRunNdsRetCode rc = runNdsFile(argv[0], argv.size(), &argv[0]);

language/English/language.txt

@@ -275,5 +275,6 @@ favorites = Favorites
 
 [loader]
 text = Use ROM loader
+not found = Loader not found
 
 [end]